Power Spectrum in Krein Space Quantization

The power spectrum of scalar field and space-time metric perturbations produced in the process of inflation of universe, have been presented in this paper by an alternative approach to field quantization namely, Krein space quantization (Gazeau et al. in Class. Quantum Gravity 17:1415, 2000; Takook in Int. J. Mod. Phys. E 11:509, 2002; Rouhani and Takook in ). Auxiliary negative norm states, the modes of which do not interact with the physical world, have been utilized in this method. Presence of negative norm states play the role of an automatic renormalization device for the theory.     

Singular Continuous Spectrum for a Class of Substitution Hamiltonians II

We consider discrete one-dimensional Schrödinger operators with aperiodic potentials generated by primitive substitutions. Using the three-block version of Gordon's criterion, we establish purely singular continuous spectrum with probability one provided that the potentials have index greater than three. It is also shown that one cannot use this criterion to prove uniform results.     

极限热环境下大功率PCB散热改进研究

通过改进太阳罩结构、改变PCB安装形式、设置隔热等方式,对大功率PCB在大空间极限热环境下的散热方式进行了优化和数值模拟。研究结果表明,根据不同发热电子元件的功率及其在PCB上的安装位置及与PCB的连接形式,采用上述措施,可以显著改善散热效果。     

IS THERE UNIT ROOT IN THE NITROGEN OXIDES EMISSIONS: A MONTE CARLO INVESTIGATION?

Abstract Use of the time‐series econometric techniques to investigate issues about environmental regulation requires knowing whether air pollution emissions are trend stationary or difference stationary. It has been shown that results regarding trend stationarity of the pollution data are sensitive to the methods used. I conduct a Monte Carlo experiment to study the size and power of two unit root tests that allow for a structural change in the trend at a known time using the data‐generating process calibrated to the actual pollution series. I find that finite sample properties of the Perron test are better than the Park and Sung Phillips‐Perron (PP) type test. Severe size distortions in the Park and Sung PP type test can explain the rejection of a unit root in air pollution emissions reported in some environmental regulation analyses.     

FURTHER APPLICATIONS OF POLAR COORDINATES IN Cn

Simplify the proof on the domain of convergence of multiple power series and consider the case where some of z1, · · · , zn are contained only in a finite number of terms of the series. Obtain some results on holomorphic functions in Cn.     

Surgénérateurs ; l'état des matériaux aux hautes irradiations, hautes puissances locales et températures, leurs gradients et propriétés mécaniques adaptées aux contraintes qui en résultent

The motivations to realize nuclear breeder reactors are developed in the present context of a strong growth in electronuclear power stations in many countries, using mostly moderated and water cooled reactors.The past studies can be of a substantial profit in France and, to a lesser degree, in other countries of the EU. However, to use fully the 238 uranium isotope, the materials for these breeders must withstand much harder radiation than those for water reactors. The power densities and thermal gradients will also be much more intense. The mechanical stresses, both static and dynamic, will be large and will act on materials with altered mechanical properties. Fuel elements will have to be produced with materials already irradiated several times and therefore showing such alterations.A field of studies concerning materials and their mechanical behavior in new and severe conditions is sketched here, both in construction and working conditions, together with proposed necessary instrumentation and research orientations.     

Electronic spectra of uranium tetrachloride clusters with electron-donor ligands

Electronic absorption spectra of nanoclusters of uranium tetrachloride are obtained experimentally and analyzed over a wide spectral range, from the visible to the IR. The structure of the long wavelength electronic absorption spectra is discussed in terms of the structure and electron-donor number of the attached ligand. Molecules of dimethyl sulfoxide (DMSO), hexamethyl phosphotriamide (HMPT), and water were used as ligands. The effect of the symmetry of the surroundings of the U⁴⁺ ion on the structure of the electronic spectrum is examined. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 76, No. 2, pp. 182–187, March–April 2009.     

正常金属d_(x~2-y~2)+id_(xy)混合波超导结中的隧道谱

在Blonder-Tinkham-Klapwijk散射理论框架下,通过求解Bogoliubov-deGennes方程,计算正常金属dx2-y2+idxy混合波超导结中的准粒子输运系数和隧道谱。研究表明:隧道谱中的电导峰位置强烈地依赖电子的入射角、超导的晶轴方位和dxy波分量的强度。     

各向异性光子晶体中Λ型原子动力学性质研究

讨论了各向异性光子晶体中外驱动场作用下Λ型原子的动力学性质及辐射谱特性. 通过理论 分析和数值计算发现，原子上下能级的布居数将出现准周期性振荡的性质，其振荡的频率和 振荡的幅度与上能级的耗散系数γ， 驱动场的作用强度，驱动场和共振频率失谐度δ等相 关； 原子上能级与光子晶体带边的相对位置将直接影响到原子自发辐射的模式. 此外，从 辐射谱的角度分析光子晶体对原子周围辐射场的特性及其传输性质的影响.